• Safety and Health at Work
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• v.9 no.4
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• pp.454-461
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• 2018

Background: Working conditions and psychosocial work factors have acquired an important role explaining the well-being and performance of professional drivers, including those working in the field of public transport. This study aimed to examine the association between job strain and the operational performance of public transport drivers and to compare the expositions with psychosocial risk at work of three different types of transport workers: taxi drivers, city bus drivers, and interurban bus drivers. Method: A sample of 780 professional drivers was drawn from three transport companies in Bogota (Colombia). The participants answered the Job Content Questionnaire and a set of sociodemographic and driving performance questions, including age, professional driving experience, work schedules, and accidents and penalties suffered in the last 2 years. Results: Analyses showed significant associations between measures of socio-labor variables and key performance indicators such road traffic accidents and penalties. Furthermore, multiple linear regression analysis contributed to explain significantly suffered accidents from key variables of the Job Demand-Control model, essentially from job strain. In addition, throughout post-hoc analyses, significant differences were found in terms of perceived social support, job strain, and job insecurity. Conclusion: Work stress is an issue that compromises the safety of professional drivers. This research provides evidence supporting a significant effect of job strain on the professional driver's performance. Moreover, the statistically significant differences between taxi drivers, city bus drivers, and interurban bus drivers in their expositions to work-related stress suggest the need for tailored occupational safety interventions on each occupational group.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.17 no.3
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• pp.46-58
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• 2018

DRT should have higher positive benefits to become the public transit than the current backcountry buses having demand deficiency and operation problems. The study examines the factors for activating DRT through importance and performance analysis(IPA) and applies the IPA gap theory to find relationship between the current buses and DRT in the mixed operation area. As a result, the operation area is the urgent improving factor and the next ones are transfer related factors, on-time arrival, safe driving, operation time and vehicles. According to the gap theory to activate DRT and reduce the current bus system, in the case that performance is smaller than importance, the performance of transfer, operating time and area, and vehicles should be up. In the case that performance is higher than importance, the performance of luggage space, vehicle clean, safe driving, operator kindness, transfer, operating elements, and fare should keep going.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.30 no.4
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• pp.9-22
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• 2022

With the continuous increase in demand for air transport services and the growth of the air transport industry, the International Civil Aviation Organization (ICAO) and its member states are facing social demands to expand the capacity of the air transport system and improve the efficiency of its operation. ICAO developed the concept of Performance Based Navigation (PBN) for the purpose of solving problems related to the function and performance of the navigation system. Member countries established an implementation plan in accordance with the resolutionof the ICAO General Assembly, and South Korea established a Performance-Based Navigation implementation plan in December 2009. This paper evaluates the progress made so far based on Korea's Performance-Based Navigation implementation plan and proposes a development direction for Performance-Based Navigation based on changes in the international environment.

• Membrane Journal
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• v.13 no.2
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• pp.125-129
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• 2003

A remarkable separation performance of olefin/paraffin mixtures has been observed through facilitated olefin transport membranes consisting of silver ions dissolved in polymer matrices. In this research, valine, an amino acid, was introduced in poly (2-ethyl-2-oxazoline) (POZ)/$AgBF_4$ membranes to increase the separation performance. FT-IR spectra show that the cationic sites ($-NH_3^+$) of valine interact with the counter anion of the silver salt, resulting in the enhanced activity of the silver ions and consequently improved separation perfornance. Therefore, the $POZ/AgBF_4$ membranes containing valines exhibit the higher permeance as well as the higher selectivity of propylene/propane than those without valine.

• JSTS:Journal of Semiconductor Technology and Science
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• v.13 no.6
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• pp.635-646
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• 2013

This technical paper contains the information of the Dye-Sensitized Solar Cells (DSSC) working principal where diffusion mechanism acts as electron transport to absorb the sunlight energy to generate the electrical energy. DSSC is photo electrochemical cell that implements the application of photosynthesis process. The performance of electron transport in DSSC has been reviewed in order to enhance the performance and efficiency of electron transport. The improvement of the electron transport also discussed in this paper.

• IEMEK Journal of Embedded Systems and Applications
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• v.10 no.6
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• pp.381-390
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• 2015

The efficient design of a transport protocol contributes to energy conservation as well as performance improvement in wireless sensor networks (WSNs). In this paper, a node-density-aware transport protocol (NDTP) for intra-cluster transmissions in WSNs for monitoring physical attributes is proposed, which takes node density into account to mitigate congestion in intra-cluster transmissions. In the proposed NDTP, the maximum active time and queue length of cluster heads are restricted to reduce energy consumption. This is mainly because cluster heads do more works and consume more energy than normal sensor nodes. According to the performance evaluation results, the proposed NDTP outperforms the conventional protocol remarkably in terms of network lifetime, congestion frequency, and packet error rate.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.16 no.8
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• pp.691-697
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• 2004

Experimental study is carried out to investigate the heat transport capability and thermal resistance of sinusoidal axially grooved heat pipe, comparing its performance to trapezoidal axially grooved heat pipe. As a result from this work, the heat transport capability of sinusoidal grooved heat pipe is lower than that of trapezoidal grooved heat pipe for the same size of outer diameter. As the ratio of depth to width of sinusoidal groove heat pipe is higher, the heat transport capability of heat pipe becomes higher. It is found that Aluminum-ammonia heat pipes with sinusoidal and trapezoidal grooves have good thermal resistance, below 0.1$^{\circ}C$/W at evaporator section and below 0.05$^{\circ}C$/W at condenser section.

• The KIPS Transactions:PartC
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• v.9C no.5
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• pp.627-636
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• 2002

In this paper, we investigate the interworking method between three transport mechanisms, that is, ATM transport, IP$_v$4 transport and Ip$_v$6transport, where these mechanisms are wholly used in a Mobile RAN (Radio Access Network). The proposed interworking method, called Triple Capable Node, is to implement three transport mechanisms simultaneously in a single node so that the node can communicate directly to other nodes having various transport mechanisms by using one of three transport mechanisms. In addition, we propose a dynamic algorithm which selects one among multiple transport mechanisms at run time in order to achieve better communication performance.

• Proceedings of the IEEK Conference
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• 2000.06c
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• pp.141-144
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• 2000

Current Internet and Intranet developments are focusing on network multimedia services involving the transport of real-time multimedia streams. In this paper, we present a real-time MPEG2 Encoding/Decoding systems and a MPEG2 stream player running on client systems based on real-time transport protocol(RTP). The MPEG2 player has been implemented by using JMF and java applet. We have tested our prototype systems with one of possible multimedia sources, camcoder, to verify its functional correctness and measure its performance.

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.1805-1808
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• 2006

In this paper, we describe a versatile use of fullerene(C60) as a charge transporting material for organic light-emitting diodes. The use of fullerene as a buffer layer for an anode, a doping material for hole transport layer, and an electron transport layer was investigated. Fullerene improved the hole injection from an anode to a hole transport layer by lowering the interfacial energy barrier and enhanced the lifetime of the device as a doping material for a hole transport layer. In addition, it was also effective as an electron transporting material to get low driving voltage in the device.